Microlens arrays are used in optoelectronic appliances such as liquid-crystal projectors, video cameras, view finders, and portable TVs. For example, a microlens array is used for the purpose of obtaining the effect of condensing the light from an LED array or the effect of improving the luminance of an LED array (see, JP-A-2005-276849). Furthermore, acrylic resins are known as resins for producing microlens arrays (see, JP-A-2001-272507).
A possible measure in improving luminance is to heighten the power of an LED to thereby increase the quantity of light emitted. However, LEDs which emit light in an increased quantity generate heat in a larger amount. In addition, use of such LEDs results in cases where heat resistance is insufficient even when an acrylic resin is used. Accordingly, there is a desire for a microlens array having excellent heat resistance. There also is a desire for a microlens array having excellent light resistance even at the short wavelength of the blue light of LEDs.